Dehydroepiandrosterone restores right ventricular structure and function in rats with severe pulmonary arterial hypertension

Abdallah Alzoubi, Michie Toba, Kohtaro Abe, Kealan D. O'Neill, Petra Rocic, Karen A. Fagan, Ivan F. McMurtry, Masahiko Oka

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Current therapy of pulmonary arterial hypertension (PAH) is inadequate. Dehydroepiandrosterone (DHEA) effectively treats experimental pulmonary hypertension in chronically hypoxic and monocrotaline-injected rats. Contrary to these animal models, SU5416/hypoxia/ normoxia-exposed rats develop a more severe form of occlusive pulmonary arteriopathy and right ventricular (RV) dysfunction that is indistinguishable from the human disorder. Thus, we tested the effects of DHEA treatment on PAH and RV structure and function in this model. Chronic (5 wk) DHEA treatment significantly, but moderately, reduced the severely elevated RV systolic pressure. In contrast, it restored the impaired cardiac index to normal levels, resulting in an improved cardiac function, as assessed by echocardiography. Moreover, DHEA treatment inhibited RV capillary rarefaction, apoptosis, fibrosis, and oxidative stress. The steroid decreased NADPH levels in the RV. As a result, the reduced reactive oxygen species production in the RV of these rats was reversed by NADPH supplementation. Mechanistically, DHEA reduced the expression and activity of Rho kinases in the RV, which was associated with the inhibition of cardiac remodeling-related transcription factors STAT3 and NFATc3. These results show that DHEA treatment slowed the progression of severe PAH in SU5416/hypoxia/normoxia-exposed rats and protected the RV against apoptosis and fibrosis, thus preserving its contractile function. The antioxidant activity of DHEA, by depleting NADPH, plays a central role in these cardioprotective effects.

Original languageEnglish
Pages (from-to)H1708-H1718
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume304
Issue number12
DOIs
Publication statusPublished - Jun 25 2013
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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